Originally Posted by Tanker
I doubt there are any risk of a lethal electrical shock from the car battery or from a standard Honda ignition coil. It's simpler to turn off the ignition.
But if you're working near the ignition switch then it's a good idea to disconnect the negative battery since you could burn yourself or blow the fuses if your screw driver shorted the exposed ignition terminals.
Getting shocked sucks, whether it is lethal or not. Disconnecting the negative battery terminal takes 10 seconds at the most and it will eliminate any chances of shocks or blown fuses.